“I had a really weird dream last night,” your friend tells you. “I dreamed that I was trying to fly like a bird but I kept flying into clotheslines. I looked it up online, and dreams where you’re struggling to fly mean that there is someone in your life who’s standing in your way and preventing you from moving forward. I suppose that has to be my boyfriend, so maybe I’d better break up with him.” Based on what you have read in this chapter, what would you tell your friend about the reliability of dream interpretation?

During an early-morning class, you notice your friend yawning, and you ask if he slept well the night before. “On weekdays, I’m in class all day, and I work the night shift,” he says. “So I don’t sleep much during the week. But I figure it’s okay because I make up for it by sleeping in late on Saturday mornings.” Is it realistic for your friend to assume that he can balance regular sleep deprivation with rebound sleep on the weekends?

You and a friend are watching the 2010 movie Inception, starring Leonardo DiCaprio as a corporate spy. DiCaprio’s character is hired by a businessman named Saito to plant an idea in the unconscious mind of a competitor while he sleeps. According to the plan, when the competitor awakens, he will be compelled to act on the idea, to the secret benefit of Saito’s company. “It’s a cool idea,” your friend says, “but it’s pure science fiction. There’s no such thing as an unconscious mind, and no way that unconscious ideas could influence the way you act when you’re conscious.” What would you tell your friend? What evidence do we have that the unconscious mind exists and can influence conscious behaviour?